Instructions
Slide the "Power" switch located on the side of the DSi to the turn the device off if it isn't powered down already.
Eject any game cartridges that may be in your DSi.
Slide the "Power" switch to turn the DSi on.
Touch the screen with your stylus when a message appears saying "Touch Screen to Continue."
Touch the "Settings Menu" icon located in the bottom middle of the screen.
Touch the "User" icon (the one with a person symbol), followed by the "Background" icon (the one with 16 small squares). Several color choices will appear.
Select a colorful background choice by touching it with your stylus. Touch "Confirm," located in the bottom right-hand corner to confirm your choice.
Touch "Go Back," followed by "Quit" and then "Yes." This will navigate you back to the home screen. This will prompt the DSi to shut down automatically, saving your changed settings. Power the DSi back on to see, and enjoy, your colorful new background.